Edimilson Fernandes is due to travel to London for a medical at West Ham after the Hammers reportedly agreed a £5.5m fee with FC Sion.
According to The Guardian, Fernandes, who is the cousin of former Manchester City player Gelson Fernandes, will sign a four-year contract with the club once the formalities have been taken of.
Bilic has been predominantly focusing on bringing in a new striker, but has also expressed a desire to bolster his midfield options as well.
The arrival of Fernandes could spell the end of Pedro Obiang, who has been tipped with a return to Serie A.
Fernandes made 26 appearances in the Swiss Super League last season and is a product of the FC Sion youth system.